Immunohistochemical Analysis of Abnormal p16INK4A Protein Expression in Human Breast Cancer.
- Author:
Tae Jin SONG
1
;
Jeong Seok MOON
;
Eun Suk LEE
;
Jae Bok LEE
;
Won Jun CHOI
;
Gi Bong CHAE
;
Young Jae MOK
;
Jeoung Won BAE
;
Nam Hee WON
;
Bum Hwan KOO
Author Information
1. Department of Surgery, Korea University College of Medicine.
- Publication Type:Original Article
- Keywords:
p16;
INK4A;
Breast cancer;
Immunohistochemical stain
- MeSH:
Breast Neoplasms*;
Breast*;
Carcinogenesis;
Cell Cycle;
Cyclin-Dependent Kinase Inhibitor p16*;
Genes, p16;
Humans*;
Phosphotransferases
- From:Journal of the Korean Surgical Society
1999;56(3):326-333
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: The p16 protein is a cyclin-dependent kinase inhibitor (CDKI) that inhibits cell cycle progression from phase G1 to phase S in the cell cycle. Many p16 gene mutations have been noted in many cancer-cell lines and in some primary cancers. These mutated genes caused abnormal or aberrant expression of the p16 protein, which might have contributed to the malignant progression of the cells by deranging the cell cycle. This study was to examine the abnormal or aberrant expression of the p16 protein in breast cancer tissue by using p16 protein specific immunohistochemical staining. METHODS: p16-protein-specific immunohistochemical staining was performed on 31 breast-cancer tissue samples. Twenty-four cases among the 31 tissue staining slides simultaneously showed a normal breast-tissue portion on the same staining slide. Microscopic photographs of both the breast-cancer and the normal- tissue portion were taken at the same magnification to compare the statistically analyzed fraction of red or brown colored p16 stained nuclei. RESULTS: In the breast cancer tissue, 7 (22.6%) showed totally negative, with less than 5% of the nuclei staining. The completely negative cases were not related to the stage of the disease (p=0.096) or to the histopathologic grade (p=0.20). The staining ratios of the breast-cancer tissue and the normal tissue were 26.2 ( +/- 18.7)% and 72.4 ( +/- 18.8)%, respectively. In the breast-cancer tissue, the ratio of expression of the p16 protein was significantly lower than in the normal tissue (p=0.001). CONCLUSIONS: In the carcinogenesis of some breast cancers, low expression of the p16 protein may play an important role in the unlimited proliferation of tumor cell due to a loss of the cell-cycle-regulating role of the p16 protein.
